Growth performance of juvenile kuruma shrimp,Marsupenaeus japonicus (Bate) fed diets replacing fishmeal with soybean meal

A feeding trail was conducted to evaluate the effect of lowering dietary fishmeal (FM) levels while increasing levels of dehulled soybean meal (SBM) on growth, nutrient utilization and body composition of juvenile kuruma shrimp, Marsupenaeus japonicas. Five experimental diets were formulated to be isoenergetic, isolipidic and isonitrogenous with decreasing FM levels from 40 to 16% while increasing SBM from 0 to 33% respectively. Quadruplicate groups of shrimp (initial wt = 1.5 g) were fed the test diets for 56 days under the flow‐through system. There were no significant differences in final weight (g) and specific growth rate (SGR, % day) among shrimp fed FM40, FM34, FM28 and FM22 diets respectively. Growth parameters significantly decreased in shrimp when fed FM16 diet, which was the lowest level of FM. Feed intake was positively correlated with the SGR of shrimp, and the lowest one was found in shrimp fed FM16 diet. Protein gain and retention, whole body lipid, arginine and methionine significantly decreased in FM16 fed group. Thus, it is concluded that dietary FM could be reduced down to 22% with SBM without compromising growth, nutrient utilization and retention, and whole body composition of kuruma shrimp.     

Assessment of species specificity of moulting accelerating compounds in Lepidoptera: comparison of activity between Bombyx mori and Spodoptera littoralis by in vitro reporter and in vivo toxicity assays

BACKGROUND: Dibenzoylhydrazine analogues have been developed successfully as a new group of insect growth regulators, called ecdysone agonists or moulting accelerating compounds. A notable feature is their high activity against lepidopteran insects, raising the question as to whether species‐specific analogues can be isolated. In this study, the specificity of ecdysone agonists was addressed through a comparative analysis in two important lepidopterans, the silkworm Bombyx mori L. and the cotton leafworm Spodoptera littoralis (Boisd.). RESULTS: When collections of non‐steroidal ecdysone agonists containing different mother structures (dibenzoylhydrazine, acylaminoketone, tetrahydroquinoline) were tested, in vitro reporter assays showed minor differences using cell lines derived from both species. However, when compounds with high ecdysone agonist activity were examined in toxicity assays, larvicidal activity differed considerably. Of note was the identification of three dibenzoylhydrazine analogues with > 100‐fold higher activity against Bombyx than against Spodoptera larvae. CONCLUSION: The present study demonstrated that species‐specific ecdysone‐agonist‐based insecticides can be developed, but their species specificity is not based on differences in the activation of the ecdysone receptor but rather on unidentified in vivo parameters such as permeability of the cuticle, uptake/excretion by the gut or metabolic detoxification. Copyright © 2010 Society of Chemical Industry     

The complete amino acid sequence of dog beta2-microglobulin.

Dog beta2-microglobulin was purified from the urine of dogs with potassium dichromate induced tubular damage. It was purified by sequential use of anion exchange chromatography, gel filtration chromatography, and reversed-phase high performance liquid chromatography. Comparisons of the amino acid sequence of the dog protein with human, mouse, and rabbit beta2-microglobulin, indicated a high degree of similarity. The dog protein was very similar to human beta2-microglobulin in that it had a molecular weight of 11.8 kDa and contained two half-cystinyl residues. Dog and human beta2-microglobulin were demonstrably different at 24 of the 99 positions compared. The data supported the conclusion that the purified protein was dog beta2-microglobulin and that all four proteins from dog, human, mouse, and rabbit were closely related.     

Development of Babesia gibsoni in the midgut of the nymphal stage of the tick, Rhipicephalus sanguineus.

Studies were made on the development of Babesia gibsoni in the midgut of the nymphal stage of the tick, Rhipicephalus sanguineus. Six hr after repletion, merozoites of B. gibsoni, free of erythrocytes, were observed in the midgut contents of the ticks. After that, within 24 hr, those merozoites were transformed into ring-forms which were relatively large ring 1-2 microns in diameter. Later, the ring forms developed into spherical forms which were somewhat elliptical in shape and 3-4 microns in diameter. Within 2-4 days, bizarre forms (5-6 microns in diameter) developed into elongated forms (5-6 microns in length). About 5-6 days after repletion, large round or elliptic zygotes (7-9 microns in diameter) were observed in the ticks gut.     

Evaluation of Meat and Bone Meal as Replacement for Protein Concentrate in the Practical Diet for Sutchi Catfish,Pangasius hypophthalmus (Sauvage 1878), Reared under Pond Condition

An 80‐d feeding trial was conducted to evaluate meat and bone meal (MBM) as replacement of protein concentrate (PC) in practical diets for sutchi catfish, Pangasius hypophthalmus. Triplicate groups of juvenile sutchi catfish (initial weight 4.80 g) were stocked at the rate of 20,000 fish/ha in 12 earthen ponds (30 m² each). Four isocaloric diets (4.12 kcal/g) were formulated by replacing 0 (Diet 1, control), 33 (Diet 2), 67 (Diet 3), and 100% (Diet 4) PC protein with MBM. The growth parameters [final weight, % weight gain, and specific growth rate (SGR)] of fish fed Diets 1, 2, and 3 were not significantly different (P > 0.05) from each other but were significantly (P < 0.05) higher than those in Diet 4. The protein content in fish fed Diet 4 was significantly (P < 0.05) lower than the others. The total production of fish in different treatments ranged between 1917 and 2648 kg/ha/80 d. A simple economic analysis determined that the highest net profit (Tk. 52,965/ha) was obtained with Diet 2 and the lowest (Tk. 27,127/ha) with Diet 4 having 100% PC protein replacement. From the results of the study it is concluded that MBM can substitute up to 67% PC protein in catfish diet without hampering the growth and feed utilization.     

Does trade openness reduce a domestic fisheries catch?

Although trade liberalization may increase a country’s welfare, its specific effect on a country’s fishing industry has not been well studied. By decomposing the effect of international trade into four parts, i.e., scale-technique effects (ST), the indirect trade-induced composition effect (IC), the indirect effect of trade intensity through income (ITC), and the direct effect of trade intensity (DTC), this study empirically investigates the effect of trade openness on country-level fisheries production. To take into account the endogeneity of trade openness and income, we adopt the instrumental variable approach. We find that a rise in trade openness reduces fisheries catch on average. In particular, the long-run effect is large. This result implies that future production is affected by current overfishing through stock dynamics. Our decomposed elasticities indicate that the ST and ITC dominate in the trade elasticity of fisheries catch. While ST implies that overfishing would be affected by trade, ITC may either establish an “overfishing haven”, similar to a “pollution haven” in the environmental literature, or production shift of fisheries to countries with lax regulation to pass stringent regulation, which is more likely to occur in high-income countries.     

Incidence of canine Babesia gibsoni infection and subclinical infection among Tosa dogs in Aomori Prefecture, Japan

To identify the incidence of Babesia gibsoni (B. gibsoni) in Aomori Prefecture, northeastern Japan, dogs with acute B. gibsoni infection were investigated at the Animal Teaching Hospital, Kitasato University, between April 2002 and March 2003. Eighteen dogs with acute B. gibsoni infection were recognized; they were all male dogs of the fighting dog breed Tosa. Their platelet counts were below normal and their packed cell volumes (PCVs) were at various levels. We collected blood samples from 141 Tosa dogs from Aomori Prefecture and used polymerase chain reaction assay to investigate the incidence of subclinical B. gibsoni infection. We also looked into the serological abnormalities associated with thrombocytopenia or anemia in subclinical infection. Forty-one of 87 dogs (47.1%) with histories of dog fighting, and one dog of 54 without a history of dog fighting were positive for B. gibsoni; that is, 42 of 141 dogs (29.8%) showed a positive result. The mean platelet counts of dogs with subclinical infection were significantly lower and levels of anti-platelet IgG were significantly higher than levels for dogs without infection. Anti-erythrocyte membrane IgG levels were significantly higher in dogs with subclinical infections, although mean PCVs were not significantly different. Tosa dogs from Aomori Prefecture, Japan, were highly infected with B. gibsoni subclinically and this pathogen might be successfully transmitted during dog fighting. Dogs with subclinical infections were at risk of chronic thrombocytopenia, which may be due to autoimmune mechanisms.     

An experimental study of apico-aortic valved conduit (AAVC) for surgical treatment of aortic stenosis in dogs

A new valved conduit was developed using a canine aortic valve. The bioprosthetic valve was fixed with glutaraldehyde and epoxy compound (Denacol-EX313/810). A vascular graft composed of ultra-fine polyester fiber (10 mm in diameter, 200 mm in length) was used. Four dogs underwent apico-aortic valved conduit (AAVC) implantation and aortic banding (bypass group, BG), while another 4 dogs underwent aortic banding without AAVC implantation (control group, CG). Cardiac catheterization and angiocardiography were performed for assessment of hemodynamics 2 weeks and 6 months after surgery. Left ventricular systolic pressure, left ventricular end-diastolic pressure and the left ventricular-aortic pressure gradient differed significantly (P<0.01) between the BG and CG dogs. Left ventricular angiocardiography showed patency of the valved conduit in all the BG dogs. Echocardiography was performed before and 2, 4 and 6 months after surgery, and showed that while pressure overload caused concentric myocardial hypertrophy in the CG dogs, the left ventricle dilated eccentrically in the BG dogs. Furthermore, relief of left ventricular pressure overload by AAVC was maintained.